1. Field of the Invention
The present invention relates generally to battery chargers. More particularly, the present invention relates to a portable battery recharge station that can utilize a number of different portable power sources for recharging different types of secondary batteries of a variety of portable devices.
2. Background of the Invention
Many electrical appliances and electronic devices are portable. Specific examples of portable devices include wireless telephones, laptop computers, camcorders, pocket PCs, and toys. Some of these portable devices use primary batteries, e.g., alkaline batteries. Most of them, however, are powered by different types of rechargeable or secondary batteries. Examples of the types of secondary batteries include nickel-cadmium (NiCd), nickel-hydrogen (NiH2), nickel-metal hydride (NiMH), lithium ion (Li-ion), lithium polymer (Li-polymer), and lead acid batteries. Although zinc-air batteries have been widely used as primary batteries, they are also gaining popularity for use as secondary batteries.
Portable devices become disabled or inoperable when the power of their batteries drop below certain threshold. At that time, users of the portable devices must either replace depleted primary batteries with new primary batteries, or find a power source to recharge secondary batteries.
As known in the art, each portable device that uses a secondary battery is equipped with a unique charger dedicated to recharge the secondary battery. In other words, a typical consumer having three different types of portable devices may have three different battery chargers. For example, the consumer may have a first battery charger for his wireless telephone, a second battery charger for his camcorder, and a third battery charger for his Pocket PC. These three battery chargers are not interchangeable. In other words, the first battery charger may not be used for the camcorder or the Pocket PC. As a result, users of these battery chargers must carry all three chargers along with their portable devices. Accordingly, there is a need for a universal battery charger for multiple portable devices.
A typical secondary battery can be recharged using one of two power sources. For example, the typical secondary battery can be recharged by one battery charger adapted to receive energy from an electrical wall outlet. In addition, the typical secondary battery can be recharged by another battery charger adapted to receive electrical energy from a cigarette lighter outlet of an automobile. There are many situations in which neither of the power sources is available. For example, an explorer who is out in the field for days or weeks at a time may endanger himself when his wireless communication device becomes inoperable due to a depleted battery. Similarly, a news crew member can lose valuable opportunities when its camcorder runs out of battery during an important news coverage at a place where no power source is available. Accordingly, there is a need for a portable battery recharge station that can recharge secondary batteries with a portable power source.
There are a number of battery chargers known in the art. For example, U.S. Pat. No. 5,343,136 (the “Yamaguchi patent”) discloses a charger having a chargeable battery with a larger current capacity than a target chargeable battery of a cordless telephone. The charger disclosed can only be used to recharge its associated target chargeable battery.
U.S. Pat. No. 5,396,162 (the “Brilmyer patent”) discloses a portable battery charger that utilizes an assembly of primary battery cells to recharge the rechargeable battery of a battery appliance. The portable battery charger disclosed is limited to using primary battery cells as its portable power source.
U.S. Pat. No. 5,565,756 (the “Urbish patent”) discloses a microprocessor controlled portable battery charger for use with a variety of battery packs. The charger disclosed can use either primary or secondary batteries as its portable power source. The charger requires charging, sensing, identifying, and output means to properly recharge the battery packs.
U.S. Pat. No. 6,154,007 (the “Shaver patent”) discloses a battery charging system that enables rapid recharging of a working battery without the need for current limit and/or over-voltage protection. The portable battery charging system disclosed, however, must always have a greater number of cells than the number of cells in the working battery.
Various technologies related to rechargeable batteries are further disclosed in other U.S. patents. For example, U.S. Pat. Nos. 5,747,968 and 5,773,959 (the “Merritt patents”) disclose lithium polymer battery charging methods and apparatus. U.S. Pat. No. 5,645,960 (the “Scrosati patent”) discloses a thin film lithium polymer battery. U.S. Pat. Nos. 6,091,230 and 6,166,548 (the “Winzer patents”) discloses a voltage recovery method for a zinc-air battery and a method of detecting battery capacity of a zinc-air battery, respectively. U.S. Pat. No. 6,146,781 (the “Surampudi patent”) discloses a direct methanol feed fuel cell and system. U.S. Pat. No. 5,352,967 (the “Karl-Diether patent”) discloses a charging method for NiCd and NiH cells. U.S. Pat. No. 6,043,631 (the “Tsenter patent”) discloses a method for charging NiCd, NiH2 and NiMH batteries.
Each of the above-referenced U.S. patents is incorporated herein by reference in its entirety.